MOS transistors such as MOSFETs (Metal Oxide Semiconductor Field-Effect Transistors) or IGBTs (Insulated Gate Bipolar Transistors) are widely used in automotive, industrial, or consumer electronic applications for driving loads, converting power, or the like. MOS transistors are voltage controlled devices that include an internal capacitance (often referred to as gate-source capacitance) formed by a gate electrode, a gate dielectric and body and source regions. The MOS transistor can be switched on and off by charging and discharging the internal capacitance, wherein switching on includes one of charging and discharging the internal capacitance, and switching off includes the other one of charging and discharging the internal capacitance. For example, in an enhancement type MOS transistor, switching on the MOS transistor includes charging the internal capacitance and switching off the MOS transistor includes discharging the internal capacitance.
Modern MOS transistors for switching electrical loads may have a voltage blocking capability of several 10V up to several 100V but may be designed to withstand voltages of only several volts, such as less than 5V or even less than 3V at their internal capacitance (at the gate node). Furthermore, it is desirable to switch those MOS transistors at high frequency, that is, to charge and discharge the internal capacitance at a high rate.
There is therefore a need for an electronic drive circuit that is capable of driving a capacitive load at a high frequency without exceeding a predefined voltage threshold across the capacitive load.